Small reactor fuel assembly loading and unloading device for nuclear power plants

Abstract

This invention discloses a fuel assembly loading and unloading device for small modular reactors (SMRs) in nuclear power plants, comprising an actuator, a drive mechanism, a positioning mechanism, a self-locking mechanism, and a lifting mechanism. The actuator is used to grab or release fuel assemblies; the drive mechanism is connected to the positioning mechanism and is used to drive the actuator to move; the self-locking mechanism is used to lock the actuator when it is in a grabbing or releasing state; the lifting mechanism is movably connected to the positioning mechanism, and the lifting mechanism can drive the self-locking mechanism to lock or unlock the actuator and the drive mechanism. This fuel assembly loading and unloading device for SMRs utilizes a self-locking mechanism to lock the actuator when it is in a grabbing or releasing state, and utilizes the lifting mechanism to drive the self-locking mechanism to lock or unlock the actuator, reliably locking the grabbing state of the fuel assembly and preventing the fuel assembly from falling during hoisting, thus improving the stability and safety of the fuel assembly loading and unloading device during operation.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant fuel assembly handling technology, and in particular to a fuel assembly loading and unloading device for small modular reactors (SMRs) in nuclear power plants. Background Technology

[0002] After each operating cycle, a small modular reactor (SMR) requires a shutdown and refueling. During refueling, fuel assemblies are removed from the reactor core using a fuel assembly loading and unloading system. Then, some spent fuel assemblies are replaced with new fuel assemblies, and finally, all fuel assemblies are reloaded into the reactor core using the same system. The fuel assembly loading and unloading system operates the fuel assemblies using its lifting mechanism.

[0003] The shape of the small reactor fuel assembly is as follows Figure 10 As shown, the fuel loading and unloading device should be suitable for this type of fuel assembly. Furthermore, to improve the efficiency of core fuel assembly loading and unloading, the device should be able to control the grabbing and releasing of fuel assemblies via its electrical control system, eliminating the need for manual operation. Fuel assembly operation is directly related to safety; the device should reliably operate the fuel assemblies and prevent accidental detachment or damage during handling. Currently, there is no fuel loading and unloading device perfectly compatible with this type of fuel assembly. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a device for loading and unloading fuel assemblies for small modular reactors in nuclear power plants.

[0005] The technical solution adopted by the present invention to solve its technical problem is: to construct a fuel assembly loading and unloading device for a small modular reactor in a nuclear power plant, which includes an actuator, a drive mechanism, a positioning mechanism, a self-locking mechanism and a lifting mechanism;

[0006] The actuator is used to grab or release fuel assemblies;

[0007] The driving mechanism is connected to the positioning mechanism and is used to drive the actuator to move;

[0008] The self-locking mechanism is used to lock the actuator when it is in a gripping state or a releasing state.

[0009] The lifting mechanism is movably connected to the positioning mechanism, and the lifting mechanism can drive the self-locking mechanism to lock or unlock the actuator and the drive mechanism.

[0010] In some embodiments, the positioning mechanism includes a fixed sleeve, a support tube connected to the fixed sleeve, and a support plate connected to the support tube.

[0011] In some embodiments, the driving mechanism includes a driver connected to the support plate, a first driving rod connected to the output end of the driver, a second driving rod connected to the lower end of the first driving rod, and a driving sleeve connected to the lower end of the second driving rod. The driving sleeve is located inside the fixed sleeve and can move along the height direction of the fixed sleeve.

[0012] In some embodiments, the positioning mechanism further includes a sensor bracket connected to the support tube, a first limit switch being mounted on the sensor bracket, and a second limit switch being mounted on the support plate;

[0013] A sensor is connected to the first drive rod, and the sensing end of the sensor is located between the first limit switch and the second limit switch.

[0014] In some embodiments, the positioning mechanism further includes a limiting roller, the limiting roller including a roller body and a roller limiting part, the roller body being fixedly mounted on the fixed sleeve, and the driving sleeve having a limiting groove for accommodating the roller limiting part;

[0015] The roller limiting part cooperates with the limiting groove to limit the displacement of the drive sleeve.

[0016] In some embodiments, the lifting mechanism includes a locking sleeve disposed on the outer periphery of the fixed sleeve and movable along the height direction of the fixed sleeve, an upper sleeve fixedly connected to the locking sleeve, a top plate fixedly connected to the upper sleeve, a bottom plate connected to the top plate, a pulley bracket connected to the bottom plate, and a fixed pulley connected to the pulley bracket.

[0017] In some embodiments, the nuclear power plant small modular reactor fuel assembly loading and unloading device further includes a lifting device, which is connected to the fixed pulley via a wire rope and is used to drive the lifting mechanism to move up and down.

[0018] In some embodiments, the upper and lower ends of the fixed sleeve are respectively provided with an upper limit portion and a lower limit portion, and the locking sleeve is installed between the upper limit portion and the lower limit portion. The upper limit portion and the lower limit portion are used together to limit the displacement of the locking sleeve.

[0019] In some embodiments, the self-locking mechanism includes a first locking member fixedly connected to the drive sleeve, a locking ball connected to the fixed sleeve, and a second locking member fixedly connected to the locking sleeve.

[0020] In some embodiments, the first locking member is provided with a first locking groove and a second locking groove, wherein the first locking groove is located above the second locking groove;

[0021] The second locking member is provided with a third locking groove;

[0022] The lifting device can drive the locking sleeve to move relative to the fixed sleeve so that the third locking groove corresponds to or is offset from the position of the locking ball. When the third locking groove corresponds to the position of the locking ball, the locking ball abuts against the third locking groove, and the driving sleeve is in the unlocked state.

[0023] When the third locking groove is misaligned with the locking ball, if the locking ball simultaneously abuts against the side wall of the second locking member and the first locking groove, the drive sleeve is in a locked state, so that the actuator is in a locked release state.

[0024] When the third locking groove is misaligned with the locking ball, if the locking ball simultaneously abuts against the side wall of the second locking member and the second locking groove, the drive sleeve is in a locked state, so that the actuator is in a locked gripping state.

[0025] In some embodiments, the positioning mechanism further includes an intermediate sleeve connected to the lower end of the fixed sleeve, a lower sleeve connected to the lower end of the intermediate sleeve, a guide sleeve connected to the lower end of the lower sleeve, and a positioning pin fixedly connected to the guide sleeve.

[0026] The locating pin is used to position itself in the center hole at the top of the fuel assembly.

[0027] In some embodiments, the driving mechanism includes a third driving rod connected to the lower end of the driving sleeve, a lever connected to the lower end of the third driving rod, and a pin fixedly connected to the side wall of the lever.

[0028] In some embodiments, the positioning mechanism includes a rotating shaft fixed within the guide sleeve;

[0029] The actuator includes a shift fork rotatably connected to the rotating shaft, the shift fork having a guide groove, and the pin being correspondingly disposed in the guide groove and movable up and down within the guide groove;

[0030] When the pin is located at the upper part of the guide groove, the actuator is in the released state; when the pin is located at the lower part of the guide groove, the actuator is in the gripping state.

[0031] In some embodiments, the actuator further includes a claw hook shaft connected to the fork and a pair of claw hooks connected to the claw hook shaft, the pair of claw hooks being respectively located at both ends of the claw hook shaft.

[0032] The present invention has the following beneficial effects: the fuel assembly loading and unloading device for small modular reactors in nuclear power plants can use an actuator to grab the fuel assembly, and use a drive mechanism to drive the actuator to move. It can automatically complete the grabbing and releasing of the fuel assembly, and use a self-locking mechanism to lock the actuator when it is in the grabbing state or in the releasing state. The lifting mechanism drives the self-locking mechanism to lock or unlock the actuator, which can reliably lock the grabbing state of the fuel assembly and prevent the fuel assembly from falling during the hoisting process, thereby improving the stability and safety of the fuel assembly loading and unloading device in the operation of small modular reactors in nuclear power plants. Attached Figure Description

[0033] To more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort. In the drawings:

[0034] Figure 1 This is a schematic diagram of the overall structure of the fuel assembly loading and unloading device for a small modular reactor in a nuclear power plant according to some embodiments of the present invention;

[0035] Figure 2 yes Figure 1 Enlarged schematic diagram of the upper and middle sections;

[0036] Figure 3 yes Figure 2 Enlarged structural diagram at point A;

[0037] Figure 4 yes Figure 1 Enlarged schematic diagram of the lower half of the structure;

[0038] Figure 5 This is a structural side view of the guide sleeve in some embodiments of the present invention;

[0039] Figure 6 This is a schematic diagram showing the drive sleeve in the locked state and the claw hook in the open state;

[0040] Figure 7 This is a schematic diagram showing the drive sleeve in the unlocked state and the claw hook in the open state;

[0041] Figure 8 This is a schematic diagram showing the drive sleeve in the unlocked state and the claw hook in the gripping state;

[0042] Figure 9 This is a schematic diagram showing the drive sleeve in a locked state and the claw hook in a gripping state;

[0043] Figure 10This is an outline drawing of the small reactor fuel assembly. Detailed Implementation

[0044] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0045] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0046] Please see Figures 1 to 9 This invention relates to a fuel assembly loading and unloading device for a small modular reactor (SMR) in a nuclear power plant, as described in some embodiments. The device is applicable to SMR fuel assemblies and may include an actuator 1, a drive mechanism 2, a positioning mechanism 3, a self-locking mechanism 4, and a lifting mechanism 5. The actuator 1 is used to grip or release the fuel assembly. The drive mechanism 2 is connected to the positioning mechanism 3 and drives the actuator 1 to move. The self-locking mechanism 4 locks the actuator 1 when it is in a gripping or releasing state. The lifting mechanism 5 is movably connected to the positioning mechanism 3 and can drive the self-locking mechanism 4 to lock or unlock the actuator 1 and the drive mechanism 2.

[0047] Understandably, the fuel assembly loading and unloading device for the small modular reactor (SMR) of the nuclear power plant can use the actuator 1 to grab the fuel assembly, and the drive mechanism 2 to drive the actuator 1 to move. It can automatically complete the grabbing and releasing of the fuel assembly, and the self-locking mechanism 4 can lock the actuator 1 when it is in the grabbing state or in the releasing state. The lifting mechanism 5 drives the self-locking mechanism 4 to lock or unlock the actuator 1, which can reliably lock the grabbing state of the fuel assembly and prevent the fuel assembly from falling during the hoisting process, thereby improving the stability and safety of the fuel assembly loading and unloading device for the SMR of the nuclear power plant during operation.

[0048] like Figure 2 As shown, the positioning mechanism 3 includes a fixed sleeve 31, a support tube 32 connected to the fixed sleeve 31, and a support plate 33 connected to the support tube 32. There can be two support tubes 32. The two support tubes 32 can be connected to the fixed sleeve 31 by flanges or bolts. The support plate 33 is fixedly connected to the two support tubes 32.

[0049] The drive mechanism 2 includes a driver 21 connected to the support plate 33, a first drive rod 22 connected to the output end of the driver 21, a second drive rod 23 connected to the lower end of the first drive rod 22, and a drive sleeve 24 connected to the lower end of the second drive rod 23. The drive sleeve 24 is located inside the fixed sleeve 31 and can move along the height direction of the fixed sleeve 31. The driver 21 is preferably a cylinder, which can be connected to an external air supply system through an air pipe connector. The driver 21 is pneumatically driven and can automatically complete the operation of the fuel assembly with the help of the equipment's electronic control system, without the need for manual operation by the operator. In some other embodiments, the driver 21 can also be a hydraulic driver or an electric driver, which is not specifically limited here. In addition, the first drive rod 22 can be connected to the second drive rod 23 through a connecting threaded sleeve, and the second drive rod 23 can be connected to the drive sleeve 24 through a flange.

[0050] For example Figure 2 As shown, the positioning mechanism 3 also includes a sensor bracket 34 connected to the support tube 32. A first limit switch 35 is mounted on the sensor bracket 34, and a second limit switch 36 is mounted on the support plate 33. A sensor 15 is connected to the first drive rod 22, with the sensing end of the sensor 15 located between the first limit switch 35 and the second limit switch 36, the second limit switch 36 being located above the first limit switch 35. When the first drive rod 22 descends to the position where the actuator 1 grasps the fuel assembly, the sensing end of the sensor 15 descends accordingly to touch the first limit switch 35. When the first drive rod 22 rises to the position where the actuator 1 releases the fuel assembly, the sensing end of the sensor 15 rises accordingly to touch the second limit switch 36. The first limit switch 35 and the second limit switch 36 can send the received signals to an external control system for processing.

[0051] like Figure 3 As shown, the positioning mechanism 3 also includes a limiting roller 37. The limiting roller 37 includes a roller body 371 and a roller limiting part 372. The roller body 371 is fixedly mounted on the fixed sleeve 31. The driving sleeve 24 is provided with a limiting groove 241 for accommodating the roller limiting part 372. The roller limiting part 372 cooperates with the limiting groove 241 to limit the displacement of the driving sleeve 24. The limiting groove 241 is specifically located on the side wall of the driving sleeve 24. During the lifting or lowering of the driving sleeve 24, the roller limiting part 372 cooperates with the limiting groove 241 to limit the lifting or lowering displacement of the driving sleeve 24, thereby limiting the displacement of the driving rod and preventing excessive lifting or lowering.

[0052] like Figure 2 As shown, the lifting mechanism 5 includes a locking sleeve 51 located on the outer periphery of the fixed sleeve 31 and movable along the height direction of the fixed sleeve 31; an upper sleeve 52 fixedly connected to the locking sleeve 51; a top plate 53 fixedly connected to the upper sleeve 52; a bottom plate 54 connected to the top plate 53; a pulley bracket 55 connected to the bottom plate 54; and a fixed pulley 56 connected to the pulley bracket 55. The nuclear power plant small modular reactor fuel assembly loading and unloading device also includes a lifting device (not shown), which is connected to the fixed pulley 56 via a wire rope. The lifting device is used to drive the lifting mechanism 5 to move up and down. Understandably, the pulley bracket 55 can be bolted to the bottom plate 54, and when the nuclear power plant small modular reactor fuel assembly loading and unloading device needs to be used, it can be connected to the lifting device via a wire rope.

[0053] In addition, if Figure 3 As shown, the upper and lower ends of the fixed sleeve 31 are respectively provided with an upper limit part 311 and a lower limit part 312. The locking sleeve 51 is installed between the upper limit part 311 and the lower limit part 312. The upper limit part 311 and the lower limit part 312 are used together to limit the displacement of the locking sleeve 51 to avoid excessive lifting or lowering.

[0054] For example Figure 3 As shown, the self-locking mechanism 4 includes a first locking member 41 fixedly connected to the drive sleeve 24, a locking ball 42 connected to the fixed sleeve 31, and a second locking member 43 fixedly connected to the locking sleeve 51. The first locking member 41 is provided with a first locking groove 411 and a second locking groove 412, with the first locking groove 411 located above the second locking groove 412. The second locking member 43 is provided with a third locking groove 431.

[0055] The lifting device can move the locking sleeve 51 relative to the fixed sleeve 31, so that the third locking groove 431 corresponds to or is offset from the locking ball 42. When the third locking groove 431 corresponds to the locking ball 42, the locking ball 42 abuts against the third locking groove 431, and the driving sleeve 24 is in the unlocked state. At this time, the actuator 1 is also in the unlocked state along with the driving sleeve 24. When the third locking groove 431 is offset from the locking ball 42, if the locking ball 42 abuts against both the side wall of the second locking member 43 and the first locking groove 411, the driving sleeve 24 is in the locked state, so that the actuator 1 is in the locked and released state. When the third locking groove 431 is misaligned with the locking ball 42, if the locking ball 42 simultaneously abuts against the side wall of the second locking member 43 and the second locking groove 412, the drive sleeve 24 is in a locked state, so that the actuator 1 is in a locked gripping state.

[0056] Understandably, the second locking member 43 can be fixed to the inner side of the locking sleeve 51 by bolts, while the first locking member 41 can be fixed to the outer side of the drive sleeve 24 by bolts, and the locking ball 42 is located in the middle position between the first locking member 41 and the second locking member 43. Through the cooperation of the first locking member 41, the second locking member 43 and the locking ball 42, the position of the drive sleeve 24 can be locked, realizing reliable locking and automatic unlocking of the gripping or releasing state of the actuator 1. This can prevent the fuel assembly from falling due to accidental operation of the actuator 1 during the hoisting process, and can also avoid the need for manual operation by the operator to complete the locking and unlocking, thereby ensuring that the fuel assembly will not fall due to accidental loosening of the hook during the hoisting process.

[0057] like Figure 4 As shown, the positioning mechanism 3 also includes an intermediate sleeve 301 connected to the lower end of the fixed sleeve 31, a lower sleeve 302 connected to the lower end of the intermediate sleeve 301, a guide sleeve 303 connected to the lower end of the lower sleeve 302, and a positioning pin 304 fixedly connected to the guide sleeve 303. The positioning pin 304 is used to position itself in the central hole at the top of the fuel assembly. The fixed sleeve 31 and the intermediate sleeve 301, the intermediate sleeve 301 and the lower sleeve 302, and the lower sleeve 302 and the guide sleeve 303 can all be connected via flanges or connecting nuts. Furthermore, this lifting device can hoist other components of the nuclear power plant's small modular reactor fuel assembly loading and unloading device into position above the fuel assembly, and then lower the equipment until the positioning pin 304 is in place in the central hole at the top of the fuel assembly, at which point it stops.

[0058] For example Figure 4As shown, the drive mechanism 2 includes a third drive rod 25 connected to the lower end of the drive sleeve 24, a lever 26 connected to the lower end of the third drive rod 25, and a pin 27 fixedly connected to the side wall of the lever 26. The positioning mechanism 3 includes a rotating shaft 38 fixed inside the guide sleeve 303. The actuation mechanism 1 includes a fork 11 rotatably connected to the rotating shaft 38. The fork 11 has a guide groove 111, and the pin 27 is correspondingly disposed in the guide groove 111 and can move up and down in the guide groove 111. When the pin 27 is located at the upper part of the guide groove 111, the actuation mechanism 1 is in a released state; when the pin 27 is located at the lower part of the guide groove 111, the actuation mechanism 1 is in a gripping state. It can be understood that the third drive rod 25 can be connected to the drive sleeve 24 via a flange, and the lever 26 can be connected to the lower end of the third drive rod 25 via a key. The guide groove 111 provides a channel for the pin 27 to move up and down. In addition, the pin 27 can move down or down along the guide groove 111 under the drive of the drive mechanism 2, thereby pushing the shift fork 11 to rotate around the rotating shaft 38.

[0059] like Figure 4 and Figure 5 As shown, the actuator 1 also includes a claw hook shaft 12 connected to the fork 11 and a pair of claw hooks 13 connected to the claw hook shaft 12. The pair of claw hooks 13 are located at both ends of the claw hook shaft 12. The claw hooks 13 are used to grip or release the fuel assembly, and the claw hook shaft 12 can be fixedly connected to the fork 11. When the fork 11 rotates around the pivot 38, it drives the claw hook shaft 12 and the pair of claw hooks 13 to rotate simultaneously, thereby realizing the gripping or release of the fuel assembly.

[0060] Combine Figures 6 to 9 As shown, the operating procedures for the fuel assembly loading and unloading device of this nuclear power plant's small modular reactor are as follows:

[0061] 1. Using a steel wire rope to connect the lifting device and the fixed pulley 56, the lifting device lifts other components of the nuclear power plant's small modular reactor fuel assembly loading and unloading device and positions them above the fuel assembly. Then, the lifting mechanism 5 is lowered until the positioning pin 304 is in place in the central hole at the top of the fuel assembly, at which point it stops. A schematic diagram of the lifting device in the lifting process is shown below. Figure 6 As shown, the drive sleeve is in the locked state and the claw hook is in the open state at this time;

[0062] 2. Continue lowering the lifting mechanism 5 until the locking sleeve 51 abuts against the lower limit part 312. At this time, the locking ball 42 abuts against the third locking groove 431 of the second locking washer, causing the drive sleeve 24 to be in the unlocked state. At this time, the pin 27 is located at the upper part of the guide groove 111, and the claw hook 13 is in the open state, i.e. Figure 7 As shown, the drive sleeve is in the unlocked state and the claw hook is in the open state at this time;

[0063] 3. The entire actuator 1 is driven downward by a cylinder to move a predetermined distance, which in turn moves the first drive rod 22, the second drive rod 23, the drive sleeve 24, the third drive rod 25, and the lever 26 downward by a predetermined distance. At this time, the pin 27 moves downward synchronously to the lower position of the guide groove 111, and the lever 11 rotates around the rotating shaft 38 to a certain position, thereby pushing a pair of claw hooks 13 from the open position to the gripping position, realizing the gripping of the fuel assembly, i.e. Figure 8 As shown, the drive sleeve is in the unlocked state and the claw hook is in the gripping state at this time;

[0064] 4. Using the lifting device, lift the locking sleeve 51 until it contacts the upper limit portion 311 of the fixed sleeve 31. At this time, the locking ball 42 simultaneously abuts against the side wall of the second locking member 43 and the second locking groove 412, and the drive sleeve 24 is in a locked state. Then, the lifting device can be used to continue to transfer the fuel assembly to the target position. Throughout the lifting process, because the drive sleeve 24 is locked by the locking sleeve 51, the gripping state of the pair of claw hooks 13 is always locked, i.e. Figure 9 As shown, the drive sleeve is in a locked state and the claw hook is in a gripping state at this time, which prevents the claw from loosening due to unexpected situations during the hoisting of the fuel assembly.

[0065] The release process of the fuel assembly is the reverse process of the fuel assembly grabbing process.

[0066] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A fuel assembly loading and unloading device for a small modular reactor (SMR) in a nuclear power plant, characterized in that, It includes an actuator (1), a drive mechanism (2), a positioning mechanism (3), a self-locking mechanism (4), and a lifting mechanism (5); The actuator (1) is used to grab or release the fuel assembly; The drive mechanism (2) is connected to the positioning mechanism (3) and is used to drive the actuator (1) to move; The self-locking mechanism (4) is used to lock the actuator (1) when it is in a gripping state or in a releasing state; The lifting mechanism (5) is movably connected to the positioning mechanism (3), and the lifting mechanism (5) can drive the self-locking mechanism (4) to lock or unlock the actuator (1) and the drive mechanism (2). The positioning mechanism (3) includes a fixed sleeve (31), a support tube (32) connected to the fixed sleeve (31), and a support plate (33) connected to the support tube (32). The drive mechanism (2) includes a driver (21) connected to the support plate (33), a first drive rod (22) connected to the output end of the driver (21), a second drive rod (23) connected to the lower end of the first drive rod (22), and a drive sleeve (24) connected to the lower end of the second drive rod (23). The drive sleeve (24) is located inside the fixed sleeve (31) and can move along the height direction of the fixed sleeve (31). The positioning mechanism (3) also includes a sensor bracket (34) connected to the support tube (32), a first limit switch (35) is installed on the sensor bracket (34), and a second limit switch (36) is installed on the support plate (33). A sensor (15) is connected to the first drive rod (22), and the sensing end of the sensor (15) is located between the first limit switch (35) and the second limit switch (36).

2. The nuclear power plant small modular reactor fuel assembly loading and unloading device according to claim 1, characterized in that, The positioning mechanism (3) further includes a limiting roller (37), which includes a roller body (371) and a roller limiting part (372). The roller body (371) is fixedly mounted on the fixed sleeve (31), and the driving sleeve (24) is provided with a limiting groove (241) for the roller limiting part (372) to be accommodated. The roller limiting part (372) cooperates with the limiting groove (241) to limit the displacement of the drive sleeve (24).

3. The nuclear power plant small modular reactor fuel assembly loading and unloading device according to claim 1, characterized in that, The lifting mechanism (5) includes a locking sleeve (51) disposed on the outer periphery of the fixed sleeve (31) and movable along the height direction of the fixed sleeve (31), an upper sleeve (52) fixedly connected to the locking sleeve (51), a top plate (53) fixedly connected to the upper sleeve (52), a bottom plate (54) connected to the top plate (53), a pulley bracket (55) connected to the bottom plate (54), and a fixed pulley (56) connected to the pulley bracket (55).

4. The nuclear power plant small modular reactor fuel assembly loading and unloading device according to claim 3, characterized in that, The nuclear power plant small modular reactor fuel assembly loading and unloading device also includes a lifting device, which is connected to the fixed pulley (56) via a wire rope. The lifting device is used to drive the lifting mechanism (5) to move up and down.

5. The nuclear power plant small modular reactor fuel assembly loading and unloading device according to claim 3, characterized in that, The upper and lower ends of the fixed sleeve (31) are respectively provided with an upper limit part (311) and a lower limit part (312). The locking sleeve (51) is installed between the upper limit part (311) and the lower limit part (312). The upper limit part (311) and the lower limit part (312) are used together to limit the displacement of the locking sleeve (51).

6. The nuclear power plant small modular reactor fuel assembly loading and unloading device according to claim 4, characterized in that, The self-locking mechanism (4) includes a first locking member (41) fixedly connected to the drive sleeve (24), a locking ball (42) connected to the fixed sleeve (31), and a second locking member (43) fixedly connected to the locking sleeve (51).

7. The nuclear power plant small modular reactor fuel assembly loading and unloading device according to claim 6, characterized in that, The first locking member (41) is provided with a first locking groove (411) and a second locking groove (412), with the first locking groove (411) located above the second locking groove (412); The second locking member (43) is provided with a third locking groove (431); The lifting device can drive the locking sleeve (51) to move relative to the fixed sleeve (31) so that the third locking groove (431) corresponds to or is offset from the locking ball (42). When the third locking groove (431) corresponds to the locking ball (42), the locking ball (42) abuts against the third locking groove (431), and the driving sleeve (24) is in the unlocked state. When the third locking groove (431) and the locking ball (42) are misaligned, if the locking ball (42) simultaneously abuts against the side wall of the second locking member (43) and the first locking groove (411), the drive sleeve (24) is in a locked state, so that the actuator (1) is in a locked release state; When the third locking groove (431) is misaligned with the locking ball (42), if the locking ball (42) simultaneously abuts against the side wall of the second locking member (43) and the second locking groove (412), the drive sleeve (24) is in a locked state, so that the actuator (1) is in a locked gripping state.

8. The nuclear power plant small modular reactor fuel assembly loading and unloading device according to claim 1, characterized in that, The positioning mechanism (3) further includes an intermediate sleeve (301) connected to the lower end of the fixed sleeve (31), a lower sleeve (302) connected to the lower end of the intermediate sleeve (301), a guide sleeve (303) connected to the lower end of the lower sleeve (302), and a positioning pin (304) fixedly connected to the guide sleeve (303). The locating pin (304) is used to locate the fuel assembly in the top center hole.

9. The fuel assembly loading and unloading device for a small modular reactor (SMR) in a nuclear power plant according to claim 8, characterized in that, The drive mechanism (2) includes a third drive rod (25) connected to the lower end of the drive sleeve (24), a lever (26) connected to the lower end of the third drive rod (25), and a pin (27) fixedly connected to the side wall of the lever (26).

10. The nuclear power plant small modular reactor fuel assembly loading and unloading device according to claim 9, characterized in that, The positioning mechanism (3) includes a rotating shaft (38) fixed inside the guide sleeve (303); The actuator (1) includes a fork (11) rotatably connected to the rotating shaft (38), the fork (11) is provided with a guide groove (111), and the pin (27) is correspondingly arranged in the guide groove (111) and can move up and down in the guide groove (111); When the pin (27) is located at the upper part of the guide groove (111), the actuator (1) is in the released state; when the pin (27) is located at the lower part of the guide groove (111), the actuator (1) is in the gripping state.

11. The fuel assembly loading and unloading device for a small modular reactor (SMR) in a nuclear power plant according to claim 10, characterized in that, The actuator (1) further includes a claw hook shaft (12) connected to the fork (11) and a pair of claw hooks (13) connected to the claw hook shaft (12), with the pair of claw hooks (13) being located at both ends of the claw hook shaft (12).

Images